Display devices generally display information to a viewer. The performance of a display is described in terms of various characteristics of the display. One such characteristic is the ability of the display to absorb ambient light originated from various sources of light such as a light bulb in a room or on a street or the sun. Generally, ambient light that is incident on a display and not absorbed by the display is superimposed on the displayed information resulting in reduced image contrast. The reduced contrast due to ambient light is generally referred to as washout. Washout is especially a concern in applications where the ambient light is very bright. For example, in outdoor applications, ambient light from the sun can significantly reduce the display contrast making it difficult for a viewer to discern the displayed information. A display, such as an instrument panel used in a motor vehicle, is particularly susceptible to washout from sun light. Typically, the display is placed in a housing to reduce ambient light access to the display. The housing is generally made black to further reduce washout by reducing the amount of light that is reflected by the housing.
Another characteristic of a display is the viewing angle. It is generally desirable that the displayed information be easily viewable over a predetermined range of viewing angles along the horizontal and vertical directions. As one display characteristic is improved, one or more other display characteristics often degrade. As a result, certain tradeoffs are made in a display device in order to best meet the performance criteria for a given display application. Thus, there remains a need for displays with improved overall performance while meeting the minimum performance criteria.